The present invention relates to an improved expansion folder of the type having an accordian-pleat backbone structure.
By way of background, there is commonly in use at the present time an expansion type folder, also known as a pressboard folder, which comprises a front and rear cover fastened to each other by a fabric tap which has an accordian pleat therein. However, the accordian pleat loses its stiffness in use and eventually becomes extremely limp so that it can invert from its normal inward orientation between the covers to an orientation wherein it lies outside of the covers and therefore presents an extremely sloppy appearance. It is with overcoming the deficiency of the foregoing type of folder that the present invention is concerned.